The objective of this contract is to provide a capacity to measure pharmacokinetics of AIDS therapies in non-human primates. This contract will serve as a central resource for other contractors using non-human primates for efficacy testing of new anti-viral therapies and represents a new resource that was previously included in an SIV contract. Specifically, it will provide the capacity to obtain information on the pharmacokinetics of therapies in uninfected non-human primates and to analyze samples, gathered under other contracts, for drug levels. The non-human primate system provides a model of drug metabolism and distribution that is similar to humans. Several special models are also available, such as pregnant and infant monkeys, that reflect the changes in the populations that are infected with HIV. The non-human primate model for pharmacokinetics is an important component of the animal model program within the Developmental Therapeutics Branch. Currently, there are contracts to provide anti-HIV testing in non-human primates infected with SIV and in testing in small animal models, including the SCID-hu mouse infected with HIV, FeLV or FIV infection of cats, and Rauscher and LP-BM-5 infection of mice.